Moving screen for oil burners



March 27,1945. GAERTQER 2,372,194

MOVING SCREEN FOR OIL BURNER-S Filed Jan. 23, 1943 2 Sheets-Sheet 1 IN VENTOR. ,Mor ifz Gazer/"er March 27, 1945. M. GAERTNER MOVING SCREEN FOR dIL BURNERS Filed Jan. 23, 1943 2 Sheets-Sheet 2 145 INVENTOR.

Patented Mar. 27, 1945 U NI TED STATES PAT ENT FF 1 CE.

MovING SCREEN Fen OIL BURNERS Moritz Gaertner, Newjlorlr, N. Y. I a lication January 23, 194 3, s riarivo. 473,236 9Claims. (Cl. 158 -1) This invention :relates generally to. furnaces such as used inindustrialestablishments, buildings,. and the like. More particularly; my present invention relates vto control ;means for more efiicient heat productionzin combustion cha n bers, its more thorough absorption and delivcry, and. especially its distribution at more unified temperatures through .difierent parts of such heated by the resultant,exp1oding.,gases. .This

vice of a screen type, with relatively a large sur- 4 face area, is positioned within the combustion pacity. They are heated up to'a maximum tem -ef caused a whirl of very'hot gasesand air and I great spaces of cold,air.and partlygasified. oil fumes. The heat, reflected from .the walls.- of the combustion chamberis in most cases too far away for a completegasification, or, the-speed. of the gases is too great for themtoLbeafie ted-by the high temperature. Even cold airor gases are hard to control in comparatively small areas, but in a combustion chamber where very high and low temperatures. are constantlymoving. in a great" turmoil, from one location to the next, aflame control has." heretofore been only partly possible. This also is influenced by atmospheric conditions. 1

The results in oil burner efi'iciency ,of .combustion heretofore obtained have accordingly been unsatisfactory. A "great percentage of oil and oilgases escape unburned to the flue, in spite of anover-supplyof air o'rsteam forced into the combustion chambers.

of the firega-ses. The-partly burned-onscorched oil. changed into smoke, *hotair intermingled with soot; which easily adhered to the steam The chambers therefore had to beef very-large size, enlarging the area of the walls, which with the inefiiciently large air supply further lowered 'thetemperature.

chamber in such a'manner, as toleiztend throughout the Width oi the combustion chamber. The 'screen may comprise, for. exampleheat resisting steel tubes or pipes placed close enoughfto ab-' sorb and" deflecttheheat, frorn' the. oil burners, anda row, of links supported by, the pipes. The

tubes are arranged in substantially uniform spacing according to their weight and heat caperature of about 1000f F. so that, no d'eforma tion may occur. I The screen is "continuously moved through the; chamber, so: that its parts travel through high temperature zones of the mb r. f I

The moving screen is pref erably endless. It may be run either vertically or at almost any angle. When run at an acute anglejupwardly,

it depresses the fire gases downwardly, counter acting the tendency the flames to shoot up- Wardly. The angle of inclination 0r. positioning of the screen, relatively to particular zones of producing-elements of the'boiler. On account of its'great porosity, it acted as heat insulation which reducedrtheheat transfer from the combustion gases" to the water to be evaporated or steam to be brought up to a higher temperature.

Anobject of the present invention is to so control: incoming air and thegas mixture within the combustion chamber, and in relation also to the location of the heater or boiler pipes, may be selected according to the 7 conditions encountered. The screen is preferably moved twice across the path of the gases. A resistance is producedby the screen according to its dimensions and the spacing of its tubes and links. This equalizes the air pressure on the upwardor downward moving sections of the screen. Gases and incoming air are thereupon thoroughly mixed twice, and brought up to a temperature where all the oil is completely gasified. The screen may be made to move four times across the gases,

or two seperate screens can be employed.

The screen tubes are preferably carried by,

linked chains which are run in depressions or channels in the furnace walls, so that the high temperatures do not affect them. The screen is of sufiicient length thatthe tubes and links will not be heated to too high a temperature and will run to some extent either overhead or underneath the combustion chamber where they may be cooled off sufiiciently'. This will preheat the air sufhoiently for entry directly into the combustion chamber. The chain drive should preferably be so located that it may ,be readily serviced, and the tubes and'links replaced when necessary.

Withthe above indicated features; objects and v advantages in view, asjwell'as'others which will hereinafter appear; the invention resides in certain novel constructions and arrangements of parts, the essential features of which are herein fully described and illustrated in the accompanying drawings, in which:

Fig. l is a longitudinal cross-sectional view through an oil burner furnace containing features of the present invention.

Fig. 2 is a cross-sectional view taken along the line 2-2 of the furnace of Fig. 1.

' Fig. 3 is an enlarged exploded view'of elements of the screen.

Fig. 4 is an enlarged view of chain elements for the screen.

Figs. 5 and 6 are fragmentary views of modified forms of drive wheel and chain arrangements for the screen.

Fig. 7 is a horizontal section, partly in elevation, through a furnace embodying a modification of invention.

at the opposite ends of the tubes 56 is similar. Associated with each stud link member 57 (see Fig. 4) is a chain link 66, and other parts such as pins or rivets 61, further connecting link members such as 68, 69 to form a sprocket or roller chain driven screen assembly.

Suspended from tubes 56 are spaced heat absorbing and delivering plates 13. Plates F5 are held against lateral displacement by pins "I i. Members 56 and 13 of the screen absorb excessive heat from parts of the chamber Hi, serve to equalize the combustion of the oil. The screen also delivers the heat to incoming air in the Fig. 8 is a section taken along theline 8-8 I of Fig. '7.

Fig. 9 is 9, fragmentary plan view of a, modified form for the screen elements.

Fig. 10 is an end view of the screen of Fig 9, as seen from the line Ill-l0.

Fig. 11 is a fragmentary view of a suspension link of a screen.

Fig. 12 is a horizontal cross-sectional view taken on the line |2--|2 of Fig. 11.

The furnace of Figs. 1 and 2 comprises front wall ID, back wall supporting inclined water or steam pipes l3 of standard construction. and side walls |4, |5. These walls form the combustion chamber It for the furnace above a bottom partition Below partition I! is lower chamber 2| formed by side walls 22, 22 front wall 23, back wall 24, and base 21. The lower chamber 2| communicates with combustion chamber 6 through apertures 25 and an opening or throat 26 in partition I1.

A blower 3D is installed in wall 23. Air is urged through chamber 2| by blower 30, by cooling purposes to be described. Wall 23 also has therein air inlet apertures 3|. A nozzle 33 of an oil burner unit 34 is mounted in furnace front wall IE) .to produce the usual oil spray 32. A pulverized coal unit or similar burner may be used. Air openings 35 of usual construction are shown in burner unit 34.

. A cover or door 36 extends from the top of extended lower wall 23, affording access to the drive elements for the screen drive chain assembly 31. The drive elements comprise an electric motor 38 having a pinion 39 meshing with a gear 4|. A pinion 42 driven by gear 4| meshes with sprocket drive gear 43 mounted on shaft 44. The teeth of sprocket gear 43 are in driving relationship with chain assembly 31. Chain 31 travels over idler sprocket gears 45, 45, upper idler sprocket gears 46, 46 and 41, 41 and rearward lower idler sprocket gears 49, 49. Gear sets 45 and 49 are mounted on shafts 52; and gear sets 46 and 41 on stub shafts 53 extending from supports 54 secured on walls of the furnace.

Screen drive chain 3'! travels through opening 26 in partition H, and along and in opposed channels 55, 55 in the side walls I 4 and I5. The travelling heat equalizing screen comprises spaced cross tubes 56. Tubes 55, as shown in detail in Fig. 3, are integrally mounted with the chain assembly 3'! through stud link-members 51, and studs 58 seated on segments 59 of tubes 56. A removable segment (iii of each tube 56 fits over the associated stud 5B. Clamping plates 63, 54, having apertures 65 for bolts of usual construction, complete the assembly. The construction chamber 2 preheating said air for delivery into the combustion,chamber It. The horizontal and vertical spacing of the members 55 and 13 should be such that the refractory heat capacity of the screen will be suflicient, and close enough to vaporize even the smallest oil particles passing through the screen 31. The weight and surface area will determine the dimensions of the members, and the resistance or slowing down of the flow speed of the fire gases. Part of a standard boiler I3 is shown above the moving screen. Another section could well be located behind, or anywhere in the path of the fire gases.

The operation of the screen, in accordance with the invention is as follows. The screen is set in motion first, before'the oil burner is operated. The oil and gas supply is preferably restricted in the beginning until the refractory mass of the screen is near its maximum degree of heat required to attain the complete gasification of the oil and heat transfer. With the increasing oil supply the volume of air is also increased, cooling down the returnin screen members to protect them from overheating. This cooling down does not mean a loss of energy as the air is brought to a higher temperature and also assists a more rapid gasification. The screen should be inspected at regular intervals and worn or burned out 'parts replaced, depending on the weight of the equipment. length of service, and heat requirement.

A large amount of the fresh air supply enters through openings 5| and flows through chamber 2| and slots 25 into combustion chamber it. While the screen is in passage 2| the cooler air absorbs some of its heat and lowers its temperature to such a degree that overheating during its travel through the combustion chamber it cannot take place. The weight of the refractory parts of the screen, length of travel through chamber it, the volume of fresh air, and the speed of travel, are so balanced that the temperature of the metal parts of the screen remains as nearly constant as possible.

It is sometimes advantageous to bring the moving screen into proximity with the burner 33 so the oil spray comes into direct contact with more closely spaced and heavier members 55, '53 of the screen. The temperature of the moving screen should be considerably higher, therefore, to make the gasification almost instantaneous and complete, so that the air supply could be reduced to ahnost its theoretical minimum.

A modified suspensory element H3, similar to member 13, is shown in detail in Figs. 11 and 12. Element H3 has a lug l5, and is adapted for relative movable positioning on its tube 55. Element H3 is streamline in section as shown, having a blunt leading edge and a narrow trailing edge 16, to reduce resistance to the passage of air or gas about it. A further modified form for may" berusediinsscombustiom "chambers. of? limited? space: Top:sprocketxgearsifli', 41*." arerlike: gears:

46,. 431 of; Figs; Land-2;. although in this casezlthere is alsoia' gear 1.8: toz'bring pGUtiOIISIOft'SCBEEH chain:v

3.1. into closerrrelationshipraszshowna The sprocket'. gears 46; 41'!" shownrinwliig: I61 affordzdiflierent s em-1 94:

inclinations-for" the screen chainma l: than inl Fig. 1.

In :FigsL'Fand 82 another embodiment of the invention is shown. In this case a screenchain 3'! travels horizontally, drive pinion 42' andgear 43' being arranged for this purpose. The sectional viewFig. 7 is taken through the boundary wall structure Ii of a chamber l6, and in said structure or wall is a horizontal channel 55. The arrangement of Figs. 7 and 8 dispenses with connecting tubes, such as 56 of Figs. 1 and 2. On chain 31, are fastened horizontally spaced members 13'. Members 13' are on alternate link assemblages, and gears 59' are arranged to carry the moving chain 31'. For small households, an installation of a corrugated disk or spider would have a similar effect as the moving screen. The screen in such case would comprise, for instance, heat resisting steel rods, tubes, or pipes which are placed close enough to absorb and reflect the heat from the oil burners and rows of vertical links, supported by the pipes and spaced apart equal distances accordingto Although I have shown preferred arrangements for carrying out my invention, it is to be understood that modifications may be made therein 7 that fall within the scope and principles thereof,

as defined in the following claims.

What I' claim is: I

1. A heating apparatus having walls providing a combustion chamber, means for introducing fuel into said combustion chamber, a second chamber adjacent said combustion chamber having at least one opening communicating therewith, means for introducing air through said second chamber into said combustion chamber to burn the fuel therein and form combustion gases, rotary elements disposed in each of said chambers, a continuous flexible screen device mounted on said elements and arranged to pass through different temperature zones of said combustion chamber across the path of the combustion gases therein to equalize the heat distribution in said combustion chamber, and through said second chamber to heat the air therein; and

-means for revolving said elements and moving therein and form combustion gases, a heat transfer screen with one portion in the base chamber and another portion in the combustion chamber and disposed in the path of the combustion gases therein, said screen having a medial portion disposed in the opening, the edges of said screen being carried in said channels, and means for moving said screen: through said. chambers to equalize. the: heat distribution: in saidcombus tion-chamber and to heat" the air 'in said" base chamber. 31 A heating: apparatus having: walls providing an upper combustion chamber-and a= base chambet with atleast. one interposed communicating opening, means for introducing: fuel into said com-bustion chamber, air supplymeans for said basechaniber for introducing air into said combustion: chamber toburn the fuel therein and form combustion gases, pairs of opposedrotary elements disposed in the upper chamber, pairs of opposed rotary elements in the lower chamber, pairs of opposed rotary elements at said opening, a heat transfer screen extending across the path of combustion gases in said combustion chamber and having side endless chains disposed on said elements, transverse rigid members connecting links of said chains, and spaced heat transfer suspensory elements carried by said transverse members. I

4. An apparatus according to claim 3, in which the transverse members are hollow tubes.

. 5. An apparatus according to claim 3, in which said suspensory elements are of streamline crosssection. I

6. A heating apparatus having walls providing an upper combustion chamber and a juxtaposed base chamber, said chambers having a transverse throat therebetween, a fuel injection nozzle in said combustion chamber, air supply means for said base chamber to introduce air into said combustion chamber to burn the fuel therein and form combustion gases, rotary sprocket gears within the upper chamber carried by the side walls thereof, rotary sprocket gears mounted'in said base chamber, a pair of opposed endless sprocket chains carried by said gears, portions of said chains being closer together at said throat, transverse rigid members connecting corresponding links of said sprocket chains, spaced suspensory elements on said rigid members to form a heat transfer screen disposed in the path of combustion gases in said combustion chamber and in the path of the air in said base chamber, and means for driving said screen through said chambers.

.7. A heatingapparatus having walls providing an upper combustion chamber and a juxtaposed base chamber with at least one interposed communic'ating opening, means for introducing fuel into said combustion chamber, air supply means for said base chamber for introducing air into said combustion chamber to burn the fuel therein and form combustion gases, pairs of opposed sprocket gears disposed in said upper chamber, pairs of opposed sprocket gears in said lower chamber, pairs of opposed sprocket gears at said opening, and a heat transfer screen extending across the .path of combustion gases in said combustion chamber and comprising opposed endless side sprocket chains engaged with said gears, transverse tubes having their respective opposite ends connected to links of said chain, and spaced heat transfer members projecting from said tubes.

8. A heating apparatus including a combustion chamber and a base chamber having openings. communicating with said combustion chamber, means for introducing fuel into said combustion chamber, means for introducing air into said base chamber to burn the fuel in said combustion chamber and form combustion gases therein, an endless heat transfer screen extending at least burn the fuel thereinand form combustion gases therein, a flexible movable heat transfer device having a portion opposite said member and disposed in the path of the combustion gases,

; another portion of said device extending in said base chamber to transfer heat to the air from said supply means, and a portion passing through said opening, and means for moving said device through said chambers and opening to equalize m the heat distribution in said combustion chamber and heat the air in said base chamber.

MORITZ GAERTNER. 

